Fresh air transmission method using the replacement, rather than air-conditioning gas circulation principle and the old and new gas mixing unhealthy practices, the outdoor novelty air through the negative pressure automatically inhalation of the room, after installation in the bedroom, living room or living room window Fresh air inlet into the room, it will automatically remove dust and filter. At the same time, the corresponding indoor pipeline is connected with the air vents in several utility rooms to form a circulation system that will take away the indoor exhaust gas and concentrate on the exhalation of the exhaust air outlet, while the exhaust gas discharged will not be recycled. Old and new style of the wind a good cycle.